81 x 9 = 801. What must you do to make the this equation true?

Why is it very easy to weigh a fish?

Look at this sequence from top to bottom. What is the next number in the sequence?
1
11
21
1211
111221
312211

This is a simple one. You just have to count the number of Fs in the given sentence.

Finished Files are the result of years of scientific study combined with the experience of years.

How many did you count?

Here is a conversation between a couple who both are software professionals.

Husband: Hey! What is your date of birth?
Wife Replied Angrily: It is 591062400
Husband after doing some calculations replied, "Got It".

What is the DOB of the wife?

Can you decipher the below rebus?

PBLUESAISNUERSES

Using eight eights and addition only, can you make 1000?

Remove two matchsticks to make the below equation correct.

I am a word that begins with the letter “i.” If you add the letter “a” to me, I become a new word with a different meaning, but that sounds exactly the same. What word am I?

When Jack was six years old he hammered a nail into his favourite tree to mark his height. Ten years later at age sixteen, Jack returned to see how much higher the nail was. If the tree grew by five centimetres each year, how much higher would the nail be?